1. Field of the Invention
The invention relates to insulation devices, either thermal or acoustical, which can be used as, for example, a jacket or cover over a structure, or as an insert module into a hollow wall structure, and the like.
2. Description of the Prior Art
Various insulation devices are known. Examples of such devices are shown in U.S. Pat. No. 1,9949,677 isused on March 6, 1934 to W. F. Crawford; U.S. Pat. No. 2,365,086 issuesd on Dec. 12, 1944 to J. T. Kamowski; U.S. Pat. No. 2,817,124 issued on Dec. 24, 1957 to E. S. Dybvig; U.S. Pat. No. 4,269,890 issued on May 26, 1981 to R. Breitling et al; U.S. Pat. No. 4,282,279 issued on Aug. 4, 1981; and U.S. Pat. No. 4,403,023 issued on Sept. 6, 1983 to H. Reiss.
U.S. Pat. No. 1,949,677 shows an insulating jacket to fit about a container which has flexible walls of canvas with a layer of intertwined horsehair or felt between the canvas walls. The canvas walls are stitched together in a waffle pattern through the horsehair or felt insulation to hold the insulation in place.
U.S. Pat. No. 2,365,086 shows an insulating jacket having inner and outer sheets of convas forming the walls of the jacket with rock wool insulation material therebetween. The inner and outer sheets of canvas are sewn together at intervals to form pockets in which the insulation is placed to hold the insulation in place.
U.S. Pat. No. 2,817,124 shows a two-compartment bag with an intermediate wall separating the compartments. One compartment is filled with a porous solid insulation material such as rock wool or fiberglass and a gas of low heat conductivity. The other compartment is filled with a compressive, solid porous insulation material such as a quilt or layer of rock wool or fiberglass, or sponge rubber.
U.S. Pat. No. 4,269,890 shows a foamed insulation device and method of introducing foam insulation into a cavity. A flexible bag of a preformed configuration is installed in the cavity to be insulated. The bag includes an open neck into which a foamable material is injected into the bag. The foamable insulation material then foams in situ filling the bag which bag expands to fill the cavity.
U.S. Pat. No. 4,282,279 shows an insulating enclosure which fits around a container to function as an insulating jacket. The insulating enclosure is fabricated of two pliable sheets of covering material fastened together at their peripheries. A layer of resilient insulating material is located between the sheets. The insulating material is a polyurethane foam material.
U.S. Pat. No. 4,403,023 shows an enclosure fabricated of a thermal insulation material. A mixture of powdered optical opacifiers and fibers of ceramic fill the enclosure.
There are a number of diverse problems associated with the prior-art insulation devices known to me.
Insulating material formed of bats or mats of insulation material must be cut to a particular peripheral configuration conforming to the shape of the apparatus to be insulated. On a production basis, this requires the use of special cutting dies. This process also generates scrap material during the cutting which scrap adds to the cost of the finished product.
A further problem with mats or bats of fibrous material, such as fiberglass, mineral fiber, ceramic fiber, and the like is that during handling of the mats fibers are released into the surrounding environment. These fibers can cause irritation and other health problems to those persons exposed to the fibers.
Another problem associated with insulation devices using mats or bats of insulation material is that their application is limited to the shape of the peripheral configuration of the bat which can be practically cut or otherwise formed in the bat. When the required form of an insulation device is complicated, the insulation device is typicallly made using plastic foams or high density molded fibruous insulation instead of bats or mats. However, plastic foams and molded fibrous insulation are relatively expensive as compared to bats or mats of insulation.
Another problem with bats or mats of fiberglass insulation is that the binder is released or off-gases.
A further problem with heretofore known insulation devices using a structure having a cavity or pocket filled with insulation is that the insulation will tend to shift or settle leaving voids within the cavity or pocket. The prior-art solution was to use bats or mats of insulation material in a bag-like structure and stitch the insulation to the bag walls. This is a time consuming process requiring many stitch lines. It also results in adversely effecting the insulation capabilities along the stitch lines, and causes holes to be made in the bag walls and insulation. Further, this attempted solution will not work with loose, discrete, divided insulation material. A solution to the foregoing concerns as provided by the present invention is to use an envelope whose shape is dictated by the configuration of the apparatus to be insulated. If the shape in the apparatus which is to be insulated is of a complex shape, then the shape of the matching envelope is complex in order to conform to the space. The configuration and thickness of the envelope is dictated by the configuration of the space which is to be insulated. In the past the requirement to insulate this type of complex configuration has required the use of a high-density molded plastic foam, molded so as to closely conform to the shape complexities in the space of the apparatus to be insulated. By fabricating an envelope which matches the shape of the space, the cost concerns existing with the prior approach are resolved. Filling the envelope with the loose, discrete insulation material so as to produce a sealed insulation device (insert) resolves much of the concern over fiber irritation and the addition of a binder addresses the concern of shifting insulation. In order to maintain the envelope shape through loose, discrete insulation material is used to completely fill the envelope and the insulation insert which results is then able to be inserted into the space to be insulated in a hollow wall structure (apparatus).